The goal is to understand the molecular mechanisms by which eggs can remain in a quiescent state with respect to he synthesis of proteins; and how protein synthesis can be rapidly and specifically activated by the cytoplasm upon fertilization of eggs and during embryogenesis. Control of protein synthesis will be studied in unfertilized eggs of sea urchins and sand dollars and during early embryogenesis of these organisms. Experiments are designed to analyze (1) the steps of protein synthesis that are controlled and (2) the molecular basis of this control at the implicated steps. Each mechanism for the modulation of protein synthesis will be considered for its ability to control all or part of the observed changes in in vivo protein synthetic activity.